[Labret]

fisting. un-natural yet consenting adults do it.
shit eating. un-natural yet consenting adults do it.
piss play. un-natural yet consenting adults do it.
homosexuality. un-natural yet consenting adults do it.

Just because you consent, does not mean it is natural.

So now we have an addendum to your theory of "needs". So long as the people involved are consenting, the deviant behavior now becomes natural.

Is homosexuality a benefit to the process of evolution and natural selection, or is it a hinderance?

Those are the only true measures of whether or not a behavior is "natural".

All you are proving is that some people enjoy it and consent to it. Thats it.

I want you to prove to me that mother nature and natural selection select certain populations to be homosexual and to tell me the benefits to that population for practicing homosexual behavior for that generation. As there will only be... 1 generation. A true homosexual will not breed. And if you are not breeding, your species dies.